The factors affecting pattern-forming properties in reaction development patterning were examined with polyarylates with various bisphenol moieties. The developability of the photosensitive polyarylates was dependent on the properties of the subtituent (R) in the bisphenol moieties. The development time decreased in the following order: R=C(CH3)(2) > fluorenyl unit >> phenolphthalein unit > C(CF3)(2) > SO2. This order agreed with that of the reactivity between the polyarylates and ethanolamine, and these orders can be explained by pK(a) of the bisphenol used to prepare the polyarylates. The development with NH2-R'-OH resulted in successful positive-tone pattern formation. However, pattern formation with the developers containing NH2-R'-OCH3 was unsuccessful. (c) 2006 Wiley Periodicals, Inc.